Three hundred inmates sleep in a former gymnasium at the Deuel Vocational Institution near Tracy, California, as shown in this Sept. 2009 photo. The Supreme Court will hear a case on California's prison overcrowding and access to health care in October.

Washington — The US Supreme Court agreed on Monday to examine whether a three-judge panel acted properly when it ordered the release of more than 38,000 California inmates to remedy constitutional deficiencies in prison-supplied health care.

At issue in the case is whether the three-judge panel exceeded its mandate by addressing prison overcrowding, rather than limiting its oversight to reforming medical and mental health care services to inmates.

Lawyers for a group of California inmates have been fighting for 20 years for improved medical and mental health care. Courts have ruled that the level of care in overcrowded California prisons violates the Constitution. But efforts at reform have stalled or failed as California prison populations have ballooned to roughly twice the system’s design capacity.

The Prison Litigation Reform Act authorizes a panel of federal judges to issue prisoner release orders. But such a panel may only do so when prison overcrowding is the primary cause of a violation of a federal right, and when no other relief will remedy that violation.

In January, the three-judge panel acknowledged that prison overcrowding was not the only cause of the constitutional violations. But the judges said it was the “primary cause” of the state’s failure to provide constitutionally adequate mental and physical health care.

The judges concluded that it would be impossible to reform the prison health care system until California’s overcrowding crisis was addressed. They ordered California within two years to reduce its prison population to an occupancy rate of 137.5 percent of its total design capacity.

The order would require the early release of an estimated 38,000 to 46,000 inmates.

California Governor Arnold Schwarzenegger and a group of Republican legislators are asking the high court to overturn the prisoner release order, calling it “the most sweeping intrusion into a state’s management of its correctional facilities in history.”

“This court has repeatedly instructed lower courts to exercise extreme caution in using their equitable powers to interfere with the management of prisons, particularly state institutions,” wrote Washington lawyer Carter Phillips in a brief on behalf of Gov. Schwarzenegger.

The California prison system is severely overcrowded. It was built to house 80,000 inmates but currently holds 165,000.

"Issuing such extreme and unprecedented prisoner release orders gravely threatens public safety in California,” said San Francisco lawyer Steven Kaufhold in a brief on behalf of California law enforcement and corrections officials.

Lawyers for the inmates said that some 10,000 prisoners are released on parole each month. “Releasing more low-risk prisoners on parole will not increase crime,” they wrote in their brief.

“The lower court’s opinion in this case is not, as the state suggests, policy reform hidden in judicial clothing,” Berkeley lawyer Donald Specter wrote. “It is a straightforward application of the rules set by Congress to a unique set of facts that can bear no other conclusion.”

Mr. Specter said in his brief that to reform the prisoner health care and mental health systems, it is first necessary to reduce the overall prison population. “The health care infrastructure is simply unable to deal with the vast number of prisoners,” he said.

The case, Schwarzenegger v. Plata (09-1233), will be heard during the court’s next term which starts in October.